Aurelia dropped a piece of metal into a beaker, and then she added acid to it. She saw colorless bubbles rising from the metal. The metal began to turn black. What type of change did Aurelia see?

Chemical change

Explanation:

From all indicators, Aurelia is seeing a chemical change occurring in the reaction here.

A chemical change is a change in which new substances are produced. For every chemical change:

We start off and end with:

         Metal   +     Acid →     Black metal     +    rising gaseous bubbles

Clearly, it is shown that new products are formed and this reaction is impossible to reverse in order to get the reactants back.

This is a typical chemical change.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.